Risk Management, Derivative Instruments And Hedging Activities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Derivative [Line Items]
Pre-tax deferred losses related to Effective Cash Flow Hedges	$ 144	$ 102
Amount expected to be Recognized in earnings during the next 12 months	4
Progress Energy [Member]
Derivative [Line Items]
Pre-tax deferred losses related to Effective Cash Flow Hedges	68	226
Amount expected to be Recognized in earnings during the next 12 months	5
Duke Energy Progress [Member]
Derivative [Line Items]
Pre-tax deferred losses related to Effective Cash Flow Hedges		109
Duke Energy Florida [Member]
Derivative [Line Items]
Pre-tax deferred losses related to Effective Cash Flow Hedges		$ 42